The objective of the current application is to study medically healthy patients presenting with the first onset of major depression after the age of 50 with magnetic resonance imaging (MRI) and with a comprehensive battery of neuropsychological (NP) tests. This group of patients will be compared to a group of currently depressed patients over the age of 50 who have had their first depressive episode before the age of 35 (recurrently depressed group) and to psychiatrically and medically healthy, age-matched elderly control subjects. Based upon our preliminary data, we hypothesize that: 1. The late-onset depression group will have more evidence of brain injury (primarily vascular disease) than either control group 2. Frontal and sub-frontal (periventricular) white matter lesions will be seen most frequently in the late-onset group 3. The late-onset group will have the most cognitive impairment on NP testing, demonstrating particularly poor performance on tests of frontal lobe functions. Investigating the relationship between brain injury and late-onset depression has potential implications for an enhanced understanding of brain injury and behavioral abnormalities, an increased awareness of the cognitive deficits related to clinical symptomatology, and for the late-onset depressed group, a new understanding into some causes for their less than optimal response to treatment.